Un d�a t�rrido de verano, la inspectora Elena Blanco, al frente de la Brigada de An�lisis de Casos, allana la vivienda de una familia y llega hasta la habitaci�n del hijo adolescente. En la pantalla de su ordenador se confirman sus sospechas: el chico est� viendo en directo c�mo dos encapuchados torturan a una joven. Importente, presencia el s�dico espect�culo hasta la muerte de la v�ctima. �Cu�ntas antes habr�n ca�do en manos de la Red P�rpura? La BAC ha estado investigando durante meses a esta organizaci�n que trafica con v�deos de violencia extrema en la Deep Web. Y a lo largo de todo este tiempo, Elena ha mantenido en secreto, incluso para su compa�ero, el subinspector Z�rate, su mayor temor: que la desaparici�n de su hijo, cuando no era m�s que un ni�o, pueda estar relacionada con esta trama macabra. �D�nde est� Lucas? �Qui�n es ahora? �Y qu� l�mites est� ella dispuesta a transgredir? A hot summer day, Inspector Elena Blanco, in front of the Case Analysis Brigade, paves a family's home and arrives at the teenage son's room. Her suspicions are confirmed on his computer screen: the boy is watching live how two hooded men torture a young woman. Powerless, witnessing the sadistic spectacle until the death of the victim. How many before will have fallen into the hands of the Purple Network? The BAC has been investigating this organization for months that deals with videos of extreme violence on the Deep Web. And throughout all this time, Elena has kept secret, even from her partner, the sub-inspector Z�rate, her greatest fear: that the disappearance of her son, when he was no more than a child, could be related to this macabre plot . Where is Lucas? Who is he now and what limits is she willing to transgress?